gecko-dev/browser/modules/HiddenFrame.jsm

85 строки
2.5 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
this.EXPORTED_SYMBOLS = ["HiddenFrame"];
const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
Cu.import("resource://gre/modules/PromiseUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
const XUL_PAGE = "data:application/vnd.mozilla.xul+xml;charset=utf-8,<window%20id='win'/>";
/**
* An hidden frame object. It takes care of creating a windowless browser and
* passing the window containing a blank XUL <window> back.
*/
function HiddenFrame() {}
HiddenFrame.prototype = {
_frame: null,
_browser: null,
_listener: null,
_webProgress: null,
_deferred: null,
/**
* Gets the |contentWindow| of the hidden frame. Creates the frame if needed.
* @returns Promise Returns a promise which is resolved when the hidden frame has finished
* loading.
*/
get() {
if (!this._deferred) {
this._deferred = PromiseUtils.defer();
this._create();
}
return this._deferred.promise;
},
destroy() {
if (this._browser) {
if (this._listener) {
this._webProgress.removeProgressListener(this._listener);
this._listener = null;
this._webProgress = null;
}
this._frame = null;
this._deferred = null;
this._browser.close();
this._browser = null;
}
},
_create() {
this._browser = Services.appShell.createWindowlessBrowser(true);
this._browser.QueryInterface(Ci.nsIInterfaceRequestor);
this._webProgress = this._browser.getInterface(Ci.nsIWebProgress);
this._listener = {
QueryInterface: XPCOMUtils.generateQI([
Ci.nsIWebProgressListener, Ci.nsIWebProgressListener2,
Ci.nsISupportsWeakReference]),
};
this._listener.onStateChange = (wbp, request, stateFlags, status) => {
if (!request) {
return;
}
if (stateFlags & Ci.nsIWebProgressListener.STATE_STOP) {
this._webProgress.removeProgressListener(this._listener);
this._listener = null;
this._webProgress = null;
// Get the window reference via the document.
this._frame = this._browser.document.ownerGlobal;
this._deferred.resolve(this._frame);
}
};
this._webProgress.addProgressListener(this._listener, Ci.nsIWebProgress.NOTIFY_STATE_DOCUMENT);
this._browser.document.location = XUL_PAGE;
}
};